Reaktion #532097

Reaktionsgleichung

3-Nitro-5-(trifluoromethyl)pyridin-2-ol

Phosphorus(V) oxybromide

→

title product

2-Bromo-3-nitro-5-trifluoromethyl-pyridine

Lösungsmittel

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto give a dark brown solution
2. 2
   Temperaturthe mixture was heated
3. 3
   Temperaturat reflux for 4.5 hours
4. 4
   SonstigeThe reaction mixture was quenched
5. 5
   workup.ADDITIONby pouring into vigorously stirring water (600 ml)
6. 6
   workup.ADDITIONcontaining sodium hydrogencarbonate (110 g)
7. 7
   ExtraktionThe dark brown mixture was extracted with DCM (3×200 ml)
8. 8
   Waschenthe organic phase was washed with water (200 ml) and brine (100 ml)
9. 9
   Trocknendried (MgSO4)
10. 10
    Einengenconcentrated in vacuo

Vorschrift

3-Nitro-5-(trifluoromethyl)pyridin-2-ol (31.00 g, 149 mmol) was dissolved in acetonitrile (250 ml) to give a dark brown solution. Phosphorus(V) oxybromide (85 g, 298 mmol) was added and the mixture was heated at reflux for 4.5 hours and then stirred at RT overnight. The reaction mixture was quenched by pouring into vigorously stirring water (600 ml) containing sodium hydrogencarbonate (110 g). The dark brown mixture was extracted with DCM (3×200 ml) and the organic phase was washed with water (200 ml) and brine (100 ml), dried (MgSO4) and concentrated in vacuo to afford the title product as a brown oil. 1H-NMR: [400 MHz, CDCl3, δH, 8.87 (1H, d, J=1.4 Hz, ArH), 8.39 (1H, d, J=1.9 Hz, ArH).

Quelle